The discussion about how to cook steak has been “medium rare is the best way to cook steak” for a long time now, so I think a lot of people just assume what ever doneness they like their steak cooked to must be “medium rare”.
The image would best be described as Blue, and it’s fine to take a steak blue if that’s what you prefer.
So, the interior of steak being raw is fine. Due to the nature of it, it’s unlikely there will any pathogens inside of it, perhaps on the outside because it is exposed and could have been contaminated, but the interior is safe due to being… well not being exposed. Of course there are exceptions but generally it is safe so long as the exterior has been cooked to a point where any pathogens are dead.
Ground beef is another thing entirely since any contamination that was on the outside has been mixed in, and thus it should be cooked through thoroughly.